I am enthusiastic about the insulating properties and strength of ICF construction but I really do not want styrene. I plan to build in an area with hot summers, cold winters, and high risks of both tornadoes and severe earthquakes, so I want to build a well-insulated home to seismic design class E standards. I am thinking of maybe a dome or half-cylindrical concrete shell (Quonset-hut-shaped), maybe partially bermed, and ICF seems like the best idea so far. But, ugh, the styrene. Does anyone know about forms made without it? Expanded/autoclaved concrete maybe? Concrete mixed with perlite? Some time ago there was a company with a product called Perlitecreteä that looked perfect, but it seems to have fizzled...I suspect it was made with radioactive fly ash or something else that got it taken off the US market. Anyhow it's gone and I can't find anything like it now. Whatever system I use, it must allow for rebar tied according to high seismic resistance standards. Anybody know anything that can give me some guidance? Thanks!

What's stopping you from going with a standard cast concrete wall and just putting something like Rockwool on both sides to create the traditional sandwich?
The only thing you'll be lacking are the fixture points of standard ICF ties.

I mean there are things like Nexcem out there. They use the term "ICF". But what they really are is a composite "cinder block" that you stuff insulation into, then fill with concrete.
https://youtu.be/lvdmyd8yaUA

http://velox-systems.co.uk/products

do yo have this in US basically flat boards made from wood crete --very simple to use

https://www.youtube.com/watch?v=46RoR5hMgZI

how to use velox note --no exterior wall bracing required to pour concrete

https://www.youtube.com/watch?v=AckW11zBOmE

another option for you--make whole house inconcrete including roof --definately hurricane +earth quake proof

AirCrete: https://www.domegaia.com/aircrete.html

Nexcem / Durisol cement bonded wood fiber blocks: https://nexcembuild.com/icf-wall-forms/

Also: http://faswall.com/faswall-green-building-system/?gclid=EAIaIQobChMIpcS_g5qR3wIVAl8NCh2qXwdJEAAYASAAEgJ0N_D_BwE

Posted By Lbear on 09 Dec 2018 09:13 AM

Posted By Persnickety on 07 Dec 2018 11:38 PM
I am enthusiastic about the insulating properties and strength of ICF construction but I really do not want styrene.

Curious. Why so opposed to polystyrene?

That's my question too.  Because the concrete itself doesn't HAVE much in the way of insulating properties.

ACC only has an R-Value of R-8 which is pretty bad and not even code minimum in almost all of the USA

Martin Holladay from GBA stated: “AAC walls have a very low R-value — most are in the range of R-8 to R-11 — and often require poured concrete bond beams that result in horrendous thermal bridging. GBA is not advocating the use of aerated autoclaved concrete blocks."

ICF with 2.5" of EPS on each side gives the ICF walls a R-21 and the thermal mass can be of benefit in certain climates with vast diurnal swings. Sailaway did some studies and it showed that it can perform as high as R-50 in certain scenarios.

Point is polystyrene is your friend when it comes to insulation so why hate it?

What's stopping me from going with a standard cast concrete wall and just putting something like Rockwool on both sides: In arches and domes, insulating the inner face and then plastering over it is a problem. I hope to avoid the hassle and expense of putting interior framing up at the ceiling. Also, the less stuff up there to break off and fall down in an earthquake, the better.
I hate styrene because it is toxic and polluting to manufacture, nonrecyclable, erodes to microscopic bits that interfere with lower orders of the food cycle in marine and aquatic systems, and puts out toxic gases when it melts or burns. That stuff about polystyrene having combustion products "no more toxic than cotton", which you will read here and there, is pure BS. *Total* and clean combustion of any hydrocarbon polymer, like *total* combustion of cellulose, produces only carbon dioxide, carbon soot, and water. But combustion is seldom so perfect as that, and never instantaneous. As a result, there is melting, offgassing, and release of toxic incomplete combustion products in normal burning situations. Obtaining clean combustion is a challenge even in waste incineration systems that are intended to minimize the production of toxins from burning plastics. I recognize the environmental value of excellent insulation, of course. Polystyrene products are not out of the question but I want very much to find something else. Thank you for the woodcrete link. I guess the woodcrete isn't too bad a thermal bridge? I need to aim for flat (fully concrete-filled) or waffle-type form systems I think. Screen type forms may not be strong enough. But I guess they insulate better?

If by screen types you mean "velox" --then go check it better they build 25 storey office blocks form it.
also check "spider ties --if you want something bomb proof --then that the way to go .

1: You're not going to be eating, drinking or breathing the styrene. It's going to be buried in the wall for the lifetime of your home. And a concrete home could, conceivably, last centuries.
2: If it's buried in your wall, underneath your exterior fascia and your interior wall structure, it's not going to "erode".
3: You're building a home out of concrete. I'd think you'd be putting something non-combustible on the walls and roof if you're in a fire zone. I'd also expect you to follow fire clearance guidelines. Also, ICF doesn't absolve you from meeting standard internal and external combustion-related codes calling for 4 hour burn times.

Essentially, what you're looking for, then, isn't an actual "ICF" system. You're looking for a filled concrete block system. As far as I know, all the full-fill and waffle systems are foam-backed.

I am still open to the polystyrene, or to a cement/styrene bead concrete ICF system, if that's my only viable or safest option. The poor insulating power of foamcrete (AAC) is a disappointment. In every other way it seems like an ideal form material. You can plaster or stucco directly onto foamcrete and it *sticks*, which is quite an attractive quality. It's impervious to insects and fire and unless it's made with particularly toxic fly ash it doesn't emit toxins when heated. I wonder if I might be able to find a system with blocks thick enough to make up for the poor insulating properties of the material? Gonna try.

LBear, Good point about going with a product that has a proven track record and that builders already know how to use. Anything too far out is indeed too big a risk. I agree that the styrene would be a great asset, and no liability, during my lifetime. But all my life I have been plagued with the outcomes of short-sighted, self-serving decisions that were made before I was born, and I have been blessed with the outcomes of farsighted and generous decisions made before I was born. I expect that is true of everyone here, isn't it? No lifetime is an island. I don't want anyone 30 years from now or 300 years from now to have to dispose of that styrene by means that will contribute to the problems of the generation after them. If there is no good alternative that I can realistically afford, then, well, that's how it is, and I'll use the damned stuff.

DMaceld, We've considered straw bale, tamped earth, cob, and Earthship systems. In a different climate or a different earthquake hazard zone one of those would be our preference for sure. We've narrowed it down to either reinforced concrete or a steel Quonset hut. Insulating a Quonset hut and managing ventilation and condensation issues is too daunting. So concrete and steel it is. The environmental impact of concrete is regrettable but its longevity may make up for it, and at least steel is recyclable. As you point out, perfection is, indeed, very far from attainable.

Dilettante, ScottishJohn, Arkie6, thank you for giving me those tips and points to consider.

Spider ties. Hmm!!

Also, Spider-ties might be desirable for a slightly different reason.
If you ARE "forced" to use foam, with the Spider-tie system, you are actually encapsulating the foam in a manner similar to a concrete insulation sandwich (concrete outside, concrete inside, foam in the middle).
Think of it like a cast-in-place concrete-faced SIP.

So if you're worried about breakdown into the environment AT ALL, you're pretty much safe, as it's going NOWHERE with the concrete encapsulating it.
You can then waterproof the exterior face and insulate either side with another choice of insulation.

Why not just go with Nexcem/Durisol and coat inside with lime plaster and outside with stucco. Breathable healthy structure. The system has been in use for decades but is a bit trickier to work with.